CTs on Inputs 13 and 14

Hi! I’d like to use the inputs #13 and #14 on my IotaWatt v6.

I can’t get sensible results. What am I doing wrong?

As a test, I’ve rigged up:

  • Known ~500W load, PF ~0.90
  • 100A CT on input 2
  • 50A CT on input 14
  • VT on input 0

Input 14 has the following wiring

  • tip of 3.5mm CT is connected to inner of barrel jack
  • sleeve of 3.5mm CT is connected to outer of the barrel jack

Configuration is

  • Single phase, selected ECS1050 and ECS16100 (see config.txt below)

Results (see image)

  • CT100A reads ok (input #2)
  • CT50A (input #14) is wrong
  • They are on the same active so should read the same

I’ve tried a few things:

  • tried input 13
  • reverse wiring (goes negative as expected)
  • confirmed CT on input #14 reads ok if plugged into inputs 1-14
  • checked burdens are correct (no changes required)
  • checked log (nothing untoward)
  • tried derived 3 phase and different phase angles as PF is low (no luck).
  • different VT

The config.txt is copied below:

{
	"format": 2,
	"timezone": 0,
	"update": "MINOR",
	"device": {
		"name": "IotaWatt",
		"version": 3,
		"channels": "15",
		"burden": [
			0,
			20,
			20,
			20,
			20,
			20,
			20,
			20,
			20,
			20,
			20,
			20,
			20,
			20,
			20
		]
	},
	"inputs": [
		{
			"channel": 0,
			"name": "Input_0",
			"type": "VT",
			"model": "generic",
			"phase": "3.6",
			"cal": "16",
			"vphase": 0,
			"vmult": 1
		},
		null,
		{
			"channel": 2,
			"name": "CT100A",
			"type": "CT",
			"model": "ECS16100",
			"phase": 0.6,
			"turns": 2000,
			"signed": true,
			"cal": 100,
			"vphase": 0,
			"vmult": 1
		},
		null,
		null,
		null,
		null,
		null,
		null,
		null,
		null,
		null,
		null,
		null,
		{
			"channel": 14,
			"name": "CT50A",
			"type": "CT",
			"model": "ECS1050",
			"phase": 1.6,
			"turns": 1000,
			"signed": true,
			"cal": "50.00",
			"vmult": 1
		}
	],
	"outputs": [],
	"derive3ph": true
}

The barrel jack is for using the input for a VT. When using 13 or 14 for CTs, use the 3.5 mm jacks. The 3.5mm CT jacks and 5.5mm VT jacks are mutually exclusive and dedicated to their respective purpose. When using one, the other must be unused as the switches that sense presence of a plug alter the way they are configured electrically.

Oh, right, I misunderstood.

I was hoping to get “extra” CT inputs but reflecting on the numbering of 13/14, that makes sense.

ps. The new LED is a huge improvement in usability in the field!